Attachment plug



Jan. 22, 1935. c. H. GUNTHORP ATTACHMENT PLUG Filed MaIGh'l3, 1931 7 V @E g Patented Jan. 22, 1935 UNITED STATES PATENT OFFICE Economy Fuse and Manufacturing Company,

Chicago, Ill., a corporation of New York Application March 13, 1931, Serial No. 522,213

6 Claims.

The invention relates to attachment plugs for threaded attachment to electric sockets and the like, and has reference particularly to an assembly including attachment plug and cap for the same.

An object of the invention is to provide an attachment plug employing relatively few parts which will permit of easy assembly,

A still further object is to provide a plug for threaded insertion in electric sockets and the like in which the screw shell will make electric contact with the socket and wherein a sure and positive connection will be had between the shell and one of the terminals housed within the plug, the construction permitting staking of the shell to the plug to prevent disassembly of the parts.

A still further object is to provide an attachment plug comprising a body portion which will provide housings for a plurality of terminals, one of the terminals being'fixedly secured to a closure of the body portion, the other terminal being detachable with respect to both closure and body.

With these and various other objects in view, the invention may consist of certain novel features of construction and operation, as will be more fully described and particularly pointed out in the specification, drawing and claims appended hereto.

In the drawing, which illustrates an embodiment of the device and wherein like reference characters are used to designate like parts- Figure 1 is an elevational view showing the cap and plug of the present invention in assem- 35 bled position;

Figure 2 is a longitudinal sectionahview showing cap and plug in separated relation;

Figure 3 is a perstective view of plug with parts in separated relation;

Figure 4 is a plan view of one end of the cap;

Figure 5 is a sectional view taken substantially along line 5-5 of Figure 4;

Figure 6 is a plan view of the face end of the plug; and

Figure 7 is a plan view, parts in section, of the contact end of the plug.

Referring to the drawing particularly to Figure 3, the invention is shown as including an attachment plug comprising a body portion 10 of insulating material, formed to provide a face plate 11, having a depending skirt 12. The wall of the skirt at diametrically opposite points is extended to provide exterior walls for housings for the terminals, to be described. The exterior walls are provided with threads 13, the housings being formed by the threaded exterior walls, interior walls 14 and 15 and side walls 18.

Forming a closure for the lower end of the housings is a circular button 17 of insulating material having fixedly secured thereto and lo- 5 cated centrally of the button a terminal 18, the same being fixedly mounted in a recess provided in the face of the button by means of the contact rivet 20. To locate the button in correct position on the body portion depending pins 21 are 10 provided on the same cooperating with openings 22 in the button, while projection 23 on the face of the button is adapted to have cooperative relationship with the shoulder 24 formed by cutting away a portion of the inner wall 15.

The other terminal 29 located within the housing formed by outer wall 13 and inner wall 15 is detachably fitted to the button 17 by means of the flat supporting portions 25 and 26 formed on the terminal and the notch 27 provided in the 20 periphery of the button. A screw shell 28 has its annular portion threaded, the threads thereof adapted to cooperate with threads 13 on the housings for securing the button 17 and the shell to the body portion 10. The flat portion 30 ofthe 26 screw shell is adapted to engage, when the same has been threaded to the body portion 10, the marginal edges of the button and to thus maintain the button in position forming'a closure for the open end of the body portion, in which 30 position terminals 18 and'29 are located within the housings adjacent the inner walls 14 and 15 respectively. It will be observed that with the parts in position as described, contact rivet 20 has electrical connection with the center terminal 18, while terminal 29 is electrically connected to the screw shell through engagement of the same with the supporting portion 26. The parts are held in assembled position by means of staking the screw shell to the button 17, as will 40 be clear from Figure 7 wherein portions of the screw shell are forced into openings 31 provided in the button.

Referring to Figure 6 it will be seen that the face plate 11 of the attachment plug is provided with a plurality of grooves 32 having their lowest portion adjacent the slotted openings 33, the grooves being separated by the ridge 34. The function of the grooves 32 is to facilitate the insertion of contacts blades electrically connected to conductor wires in openings 33 to engage the terminals 18 and 29 respectively.

The invention is further concerned with a novel form of cap for association with attachment plugs of the type described, the same comprising a body portion 36 of insulating material having a flaring end 3'7 and opening 38, the flaring end forming a handle providing means which can be grasped by the fingers of the hand whereby the cap can be conveniently removed from its associated plug. -The body portion 38 is provided with a cavity forming a depending skirt 40 and supporting shoulders 41', the latter providing means for sup-' porting the contact blades 42 and 43 and being provided with arcuate projections 44, as shown in Figin-e 4. Rivets 45 serve to fixedly mount the contact blades on their respective supporting portions. The cavity of the body portion 36 is provided with triangular shaped grooves 48 which begin in the upper part of the cavity and terminate adjacent the contact blades 42and 43 respectively, whereby the conductors adapted to be electrically connected to the contact blades can be individualy housed and separated from each other. Associated with the contact blades 42 and 43 are terminal screws (Figure '5) 50 and 51 respectively, the screws serving to secure the bare end of the conductors to the blades. In order to allow convenient and easy attachment of the conductor end to the blades, the terminal screws can be provided with depending peripheral portions 52 so that the wire when once located around the threaded stem of the screw will be encompassed by the depending portions, the construction permitting the screw to be rotated and yet maintaining the wire in position around the stem.

It will be seen that the above construction results in a device employing relatively few parts,

electrical connection is made between the screw shell and one of the terminals. Also the provision of housings integral with the body portion and ot a closure therefore serves to separate and to insulate the terminals from each other and further forms a sturdy structure and one wherein disassembly of the parts is easily prevented. The grooves 32 provided in the face plate have a gradual taper terminating at the lowermost point in the vicinity of the openings 38. Irrespective of the position of the contact blades 42 and 43 with respect to the openings in attempting to insert the same therein it will be seen that the grooves will guide the blades towards the openings facilitating their insertion.-

It is to be understood'that I do not wish to be limited by the exact embodiment of the device shown, which is merely by way of illustration and not limitation, as various and other forms of the device will of course be apparent to those skilled in the art without departing from the spirit of the invention or the scope of the claims.

I claim:

1. An attachment plug comprising a body portion provided with spaced housings, ea'ch housing including an outer wall having a corrugated surface, an inner wall and connecting side walls, a pair of terminals, a closure for one end of the housings, one of said terminals being fixedly mounted centrally of the closure and extending within one of the housings, said other terminal being detachably mounted on the closure and having a portion located exteriorly of the closure. and a screw shell enclosing part of the closure to engage the exterior portion of said terminal and being threaded to the body by means of the corrugations on the outer walls of said housings, said screw shell maintaining said closure in assembled relation.

2. An attachment plug comprising a body portion pro7ided with spaced housings, eaeh housing including an outer wall having corrugations on its outer surface, an inner wall and connecting side walls, projections on said housings, a pair of terminals, a closure for one end of said housings having recesses interfitting with said projections, one of said terminals being fixedly mounted centrally of the closure and extending within one of the housings, said other terminal being detachably mounted on the closure and having a portion located exteriorly of the closure, and a screw shell enclosing part of the closure to engage the exterior portion of said terminal and being threaded to the body by means or the corrugations on the outer walls of said housings, said screw shell maintaining said closure in assembled relation.

3. An attachment plug comprising a body portion having spaced housings, each housing including an outer wall having corrugations disposed on its outer surface, an inner wall and connecting side walls, projections extending from one end of the housing, and said other end being formed to provide a face plate, a notch provided in the inner wall of one of said housings, a terminal located within each of said housings, a closure for the housings having recesses interfitting with said projections and a lug for location in said notch, one of said terminals being fixedly mounted centrally of the closure, said other terminal having spaced supporting portions for detachably fitting the terminal on the closure with one supporting portion being located exteriorly of the closure, and a screw shell enclosing part of the closure to engage the exterior portion of said terminal and being threaded to the body portion by means of the corrugations on the exterior wall of said housings, said screw shell maintaining the closure in assembled relation.

4, An attachment plug comprising a body portion having spaced housings, each housing including an outer wall having corrugations disposed on its outer surface, an inner wall and connecting side walls, projections extending from one end of the housing, and said other end being formed to provide a face plate, a notch provided in the inner wall of one of said housings, a terminal located within each of said housings, a closure for the housings having recesses interfitting with'said projections and a lug for location in said notch to correctly position the closure, one of said terminals being fixedly mounted centrally of the closure, said other terminal having spaced supporting portions for detachably fitting the terminal on the closure, with one portion being located exteriorly of the closure, a screw shell enclosing Hart of the closure for enga in the exterior portion of said terminal and being threaded to the body by means of the corruga-v tions on the exterior wall of the housings, said screw shell maintaining the closure in assembled relation, and means uniting the screw shell and the closure. to prevent disassembly of the parts.

5. An attachment plug, comprising a body portion providing housings, a terminal located within each of said housings, a closure for one end of said housing, one of said terminals being fixedly mounted centrally of the closure, said other terminal having spaced supporting portions and being thereby detachably secured to the closure with one of said supporting portions being located exteriorly of the closure, and a screw shell threadedto the body, said shell contacting the exterior supporting portion and also engaging said closure to hold the same and the body portion in assembled relation.

6. An attachment plug, comprising a-body portion providing housings, a terminal located within the closure, a screw shell threaded to said body v each of said housings, a closure for one end of portion, said shell contacting the exterior,sup-

the housings, one of said terminals being fixedly porting portion and also engaging said closure mounted centrally of the closure, said other terto maintain the same and the body portion in 5 minal having spaced supporting portions, a notch assembled relation, and means uniting the screw located in the periphery of said closure for deshell and closure to prevent disassembly of the tachably seating the said terminal with one of parts.

said supporting portions located exterior-1y oi CECILH. GUNTHORP. 

